实体框架中的模型多对多(Model Many to many in Entity Framework)

实体框架中的模型多对多(Model Many to many in Entity Framework)

我需要在EF中模拟多对多的关系。 我经常遇到的答案要求两个实体互相引用。

这是我的情况。

我有一个Role实体，它可以有多个权限（“权限实体”。）Role将有一个名为权限的列表。另一方面，一个权限可以属于多个角色，但它没有role的引用属性。

我该如何建模呢？

另外，我可以使用Role级联新的权限吗？

I need to model a Many to many relation in EF. The answer I usually come across requires both entities to have each others reference.

Here is my case.

I have a Role entity, which can have multiple permissions("Permission entity). Role will have a list called permissions. On the other hand one permission can belong to multiple roles but it does not have a reference property for role.

How can I model it?

Also, can I cascade a new permission with Role?

最满意答案

使用Code-First，您可以使用此建模：

public class Role { public Role() { this.Premission = new HashSet<Premission>(); } public int RoleId { get; set; } public string RoleName { get; set; } public virtual ICollection<Premission> Premissions { get; set; } } public class Premission { public Premission() { this.Role = new HashSet<Role>(); } public int PremissionId { get; set; } public string PremissionName { get; set; } public virtual ICollection<Role> Roles{ get; set; } }

使用Fluent Api，您可以将其映射为：

protected override void OnModelCreating(DbModelBuilder modelBuilder) { modelBuilder.Entity<Role>() .HasMany<Premission>(s => s.Premissions) .WithMany(c => c.Roles) .Map(cs => { cs.MapLeftKey("RoleRefId"); cs.MapRightKey("PremissionRefId"); cs.ToTable("Role_Premission"); }); }

Using Code-First you can go with this modeling:

public class Role { public Role() { this.Premission = new HashSet<Premission>(); } public int RoleId { get; set; } public string RoleName { get; set; } public virtual ICollection<Premission> Premissions { get; set; } } public class Premission { public Premission() { this.Role = new HashSet<Role>(); } public int PremissionId { get; set; } public string PremissionName { get; set; } public virtual ICollection<Role> Roles{ get; set; } }

Using Fluent Api you can map it like:

protected override void OnModelCreating(DbModelBuilder modelBuilder) { modelBuilder.Entity<Role>() .HasMany<Premission>(s => s.Premissions) .WithMany(c => c.Roles) .Map(cs => { cs.MapLeftKey("RoleRefId"); cs.MapRightKey("PremissionRefId"); cs.ToTable("Role_Premission"); }); }